/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package org.apache.coyote.http11.upgrade;

import org.apache.coyote.Processor;
import org.apache.coyote.Request;
import org.apache.coyote.http11.upgrade.servlet31.HttpUpgradeHandler;
import org.apache.coyote.http11.upgrade.servlet31.WebConnection;
import org.apache.juli.logging.Log;
import org.apache.tomcat.util.net.AbstractEndpoint.Handler.SocketState;
import org.apache.tomcat.util.net.SSLSupport;
import org.apache.tomcat.util.net.SocketStatus;
import org.apache.tomcat.util.net.SocketWrapper;
import org.apache.tomcat.util.res.StringManager;

import java.io.IOException;
import java.util.concurrent.Executor;

public abstract class AbstractProcessor<S>
		implements Processor<S>, WebConnection {

	protected static final StringManager sm =
			StringManager.getManager(Constants.Package);
	private final HttpUpgradeHandler httpUpgradeHandler;
	private final AbstractServletInputStream upgradeServletInputStream;
	private final AbstractServletOutputStream upgradeServletOutputStream;
	protected AbstractProcessor(HttpUpgradeHandler httpUpgradeHandler,
	                            AbstractServletInputStream upgradeServletInputStream,
	                            AbstractServletOutputStream upgradeServletOutputStream) {
		this.httpUpgradeHandler = httpUpgradeHandler;
		this.upgradeServletInputStream = upgradeServletInputStream;
		this.upgradeServletOutputStream = upgradeServletOutputStream;
	}

	protected abstract Log getLog();


	// --------------------------------------------------- AutoCloseable methods

	@Override
	public void close() throws Exception {
		upgradeServletInputStream.close();
		upgradeServletOutputStream.close();
	}


	// --------------------------------------------------- WebConnection methods

	@Override
	public AbstractServletInputStream getInputStream() throws IOException {
		return upgradeServletInputStream;
	}

	@Override
	public AbstractServletOutputStream getOutputStream() throws IOException {
		return upgradeServletOutputStream;
	}


	// ------------------------------------------- Implemented Processor methods

	@Override
	public final boolean isUpgrade() {
		return true;
	}

	@Override
	public HttpUpgradeHandler getHttpUpgradeHandler() {
		return httpUpgradeHandler;
	}

	@Override
	public final SocketState upgradeDispatch(SocketStatus status)
			throws IOException {

		if (status == SocketStatus.OPEN_READ) {
			try {
				upgradeServletInputStream.onDataAvailable();
			} catch (IOException ioe) {
				// The error handling within the ServletInputStream should have
				// marked the stream for closure which will get picked up below,
				// triggering the clean-up of this processor.
				getLog().debug(sm.getString("abstractProcessor.onDataAvailableFail"), ioe);
			}
		} else if (status == SocketStatus.OPEN_WRITE) {
			try {
				upgradeServletOutputStream.onWritePossible();
			} catch (IOException ioe) {
				// The error handling within the ServletOutputStream should have
				// marked the stream for closure which will get picked up below,
				// triggering the clean-up of this processor.
				getLog().debug(sm.getString("abstractProcessor.onWritePossibleFail"), ioe);
			}
		} else if (status == SocketStatus.STOP) {
			try {
				upgradeServletInputStream.close();
			} catch (IOException ioe) {
				getLog().debug(sm.getString(
						"abstractProcessor.isCloseFail", ioe));
			}
			try {
				upgradeServletOutputStream.close();
			} catch (IOException ioe) {
				getLog().debug(sm.getString(
						"abstractProcessor.osCloseFail", ioe));
			}
			return SocketState.CLOSED;
		} else {
			// Unexpected state
			return SocketState.CLOSED;
		}
		if (upgradeServletInputStream.isCloseRequired() ||
				upgradeServletOutputStream.isCloseRequired()) {
			return SocketState.CLOSED;
		}
		return SocketState.UPGRADED;
	}

	@Override
	public final void recycle(boolean socketClosing) {
		// Currently a NO-OP as upgrade processors are not recycled.
	}


	// ------------------ Processor methods for Inbound/Outbound based mechanism

	@Override
	@Deprecated
	public UpgradeInbound getUpgradeInbound() {
		return null;
	}

	@Override
	public SocketState upgradeDispatch() throws IOException {
		return null;
	}


	// ---------------------------- Processor methods that are NO-OP for upgrade

	@Override
	public final Executor getExecutor() {
		return null;
	}

	@Override
	public final SocketState process(SocketWrapper<S> socketWrapper)
			throws IOException {
		return null;
	}

	@Override
	public final SocketState event(SocketStatus status) throws IOException {
		return null;
	}

	@Override
	public final SocketState asyncDispatch(SocketStatus status) {
		return null;
	}

	@Override
	public void errorDispatch() {
		// NO-OP
	}

	@Override
	public final SocketState asyncPostProcess() {
		return null;
	}

	@Override
	public final boolean isComet() {
		return false;
	}

	@Override
	public final boolean isAsync() {
		return false;
	}

	@Override
	public final Request getRequest() {
		return null;
	}

	@Override
	public final void setSslSupport(SSLSupport sslSupport) {
		// NOOP
	}
}
